Reference signal and transmit power ratio design for non-orthogonal transmissions

ABSTRACT

Techniques are provided for reference signal transmissions and transmit power ratio determination in non-orthogonal transmissions. A traffic-to-pilot power ratio (TPR) may be determined for a base layer for a non-orthogonal channel and another TPR may be determined for an enhancement layer for the non-orthogonal channel. Reference signal transmissions may be transmitted by a base station at a reference signal transmission power, and a user equipment (UE) may estimate channel quality for the base layer or the enhancement layer based at least in part on an energy level of the received reference signal and one or more of the first TPR or the second TPR. A base station may transmit TPR signaling that may indicate one or more TPR values for one or both of the base layer or enhancement layer.

CROSS REFERENCES

The present Application for Patent claims priority to U.S. ProvisionalPatent Application No. 62/068,933 by Sun et al., entitled “ReferenceSignal and Transmit Power Ratio Design for NOMA Transmissions,” filedOct. 27, 2014, assigned to the assignee hereof, and expresslyincorporated by reference herein.

FIELD

The present disclosure, for example, relates to wireless communicationsystems, and more particularly to techniques for reference signaltransmission and power ratio design between base layer and enhancementlayer transmissions for non-orthogonal transmissions.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be multiple-accesssystems capable of supporting communication with multiple users bysharing the available system resources (e.g., time, frequency, andpower). Examples of such multiple-access systems include code-divisionmultiple access (CDMA) systems, time-division multiple access (TDMA)systems, frequency-division multiple access (FDMA) systems, orthogonalfrequency-division multiple access (OFDMA) systems, and non-orthogonalmultiple access (NOMA) systems. Additionally, some systems may operateusing time-division duplex (TDD), in which a single carrier is used forboth uplink and downlink communications, and some systems may operateusing frequency-division duplex (FDD), in which separate carrierfrequencies are used for uplink and downlink communications.

By way of example, a wireless multiple-access communication system mayinclude a number of base stations, each simultaneously supportingcommunication for multiple communication devices, otherwise known asuser equipments (UEs). A base station may communicate with UEs ondownlink channels (e.g., for transmissions from a base station to a UE)and uplink channels (e.g., for transmissions from a UE to a basestation).

As wireless communications systems become more congested, operators areseeking ways to increase capacity. Various approaches include the use ofsmall cells, multiple-input multiple-output (MIMO) techniques, the useof an unlicensed radio frequency spectrum band, and/or the use ofwireless local area networks (WLANs) to offload some of the trafficand/or signaling of a wireless communication system. Another approachincludes the transmission of non-orthogonal downlink signals to increasethe capacity of a wireless communication system. Many of the approachesfor enhancing capacity may cause interference with concurrentcommunications in a cell. In order to provide enhanced data ratesthrough a wireless communication system, it may be beneficial toestimate and mitigate such interference.

SUMMARY

The present disclosure, for example, relates to one or more techniquesfor reference signal transmissions and transmit power ratiodetermination in non-orthogonal transmissions. In some examples, atraffic-to-pilot power ratio (TPR) may be determined for a base layerfor a non-orthogonal channel and another TPR may be determined for anenhancement layer for the non-orthogonal channel. Reference signaltransmissions may be transmitted by a base station at a reference signaltransmission power, and a user equipment (UE) may estimate channelquality for the base layer or the enhancement layer based on an energylevel of the received reference signal and one or more of the first TPRor the second TPR. A base station may, in certain examples, transmit TPRsignaling that may indicate one or more TPR values for one or both ofthe base layer or enhancement layer.

According to a first set of examples of the disclosure, a method forwireless communication is described, the method including determining afirst TPR for a base layer for a non-orthogonal channel and a second TPRfor an enhancement layer for the non-orthogonal channel; receiving atleast a portion of a reference signal of the non-orthogonal channel; andestimating channel quality for the base layer or the enhancement layerbased at least in part on an energy level of the received referencesignal and one or more of the first TPR or the second TPR.

According to the first set of examples, an apparatus for wirelesscommunications is described, the apparatus including means fordetermining a first TPR for a base layer for a non-orthogonal channeland a second TPR for an enhancement layer for the non-orthogonalchannel; means for receiving at least a portion of a reference signal ofthe non-orthogonal channel; and means for estimating channel quality forthe base layer or the enhancement layer based at least in part on anenergy level of the received reference signal and one or more of thefirst TPR or the second TPR.

According to the first set of examples, another apparatus for wirelesscommunication is described, the apparatus including a processor, and amemory in electronic communication with the processor and instructionsstored in the memory, the instructions being executable by the processorto: determine a first TPR for a base layer for a non-orthogonal channeland a second TPR for an enhancement layer for the non-orthogonalchannel; receive at least a portion of a reference signal of thenon-orthogonal channel; and estimate channel quality for the base layeror the enhancement layer based at least in part on an energy level ofthe received reference signal and one or more of the first TPR or thesecond TPR.

According to the first set of examples, a non-transitorycomputer-readable medium storing code for wireless communication isdescribed, the code comprising instructions executable by a processorto: determine a first TPR for a base layer for a non-orthogonal channeland a second TPR for an enhancement layer for the non-orthogonalchannel; receive at least a portion of a reference signal of thenon-orthogonal channel; and estimate channel quality for the base layeror the enhancement layer based at least in part on an energy level ofthe received reference signal and one or more of the first TPR or thesecond TPR.

In some aspects of the method, apparatuses, and/or non-transitorycomputer-readable medium of the first set of examples, a determinationmay be made of which of one or more transmission strategy categories isto be used for downlink transmissions from a base station to the UE overthe non-orthogonal channel; and the first TPR and the second TPR may beselected from at least one pair of first TPR and second TPR values, eachpair associated with one of the transmission strategy categories. Insome examples, signaling may be received from the base station thatprovides the one or more pairs of first TPR and second TPR values andthe transmission strategy category associated with each of the pairs ofTPR values. The signaling may be received, for example, via radioresource control (RRC) signaling. In some examples, the determiningwhich of the one or more transmission strategy categories is based atleast in part on spatial layer sharing of respective transmissionstrategies, and a first pair of TPR values is associated withtransmission strategies that use spatial layer sharing and a second pairof TPR values is associated with transmission strategies that do not usespatial layer sharing. In certain examples, the reference signal is oneor more of a cell-specific reference signal (C-RS) or a channel stateinformation reference signal (CSI-RS).

In some aspects of the method, apparatuses, and/or non-transitorycomputer-readable medium of the first set of examples, the first TPR andthe second TPR are determined based at least in part on informationcontained in a physical downlink control channel (PDCCH), and whereinthe information contained in the PDCCH comprises one or more ofprecoding matrix information, spatial layer sharing information, TPRinformation, or interference cancellation information. In some examples,the interference cancellation information may include an interferencecancellation flag, and a first pair of TPR values are to be used for thefirst TPR and the second TPR when the flag is set, and a second pair ofTPR values are to be used for the first TPR and the second TPR when theflag is cleared. In some examples, two or more pairs of TPR values maybe provided to the UE via RRC signaling, each pair of TPR valuesincluding an associated first TPR value and second TPR value. The TPRinformation may include, for example, an indication of which pair of TPRvalues are to be selected for the first TPR and the second TPR.

In some aspects of the method, apparatuses, and/or non-transitorycomputer-readable medium of the first set of examples, a demodulationreference signal (DM-RS) of a data transmission over the non-orthogonalchannel may be received, and the data transmission may be demodulatedbased at least in part on a TPR value for the received DM-RS. In someexamples, the TPR value for the received DM-RS is a sum of the first TPRand the second TPR. In certain examples, the TPR value for the receivedDM-RS is independent of one or more of the first TPR or the second TPRand may, for example, be a unity ratio. The DM-RS, in some examples, maybe associated with one of a plurality of antenna ports of thenon-orthogonal channel, and the one of the plurality of antenna portsmay be selected for estimating the channel quality based on whether theUE is to receive base layer transmissions or enhancement layertransmissions. In certain examples, a transmit power for datatransmissions for the base layer transmissions or enhancement layertransmissions corresponds to the DM-RS power of the respective baselayer or enhancement layer.

According to a second set of illustrative examples, a method forwireless communication is described. In one example the method mayinclude determining a first TPR between a base layer data transmissionand a reference signal transmission and a second TPR between anenhancement layer data transmission and the reference signaltransmission; and transmitting signaling to one or more user equipment(UE) indicating the first TPR and second TPR.

According to the second set of examples, an apparatus for wirelesscommunications is described, the apparatus including means fordetermining a first TPR between a base layer data transmission and areference signal transmission and a second TPR between an enhancementlayer data transmission and the reference signal transmission; and meansfor transmitting signaling to one or more UE indicating the first TPRand second TPR.

According to the second set of examples, another apparatus for wirelesscommunication is described, the apparatus including a processor, and amemory in electronic communication with the processor and instructionsstored in the memory, the instructions being executable by the processorto: determine a first TPR between a base layer data transmission and areference signal transmission and a second TPR between an enhancementlayer data transmission and the reference signal transmission; andtransmit signaling to one or more UE indicating the first TPR and secondTPR.

According to the second set of examples, a non-transitorycomputer-readable medium storing code for wireless communication isdescribed, the code comprising instructions executable by a processorto: determine a first TPR between a base layer data transmission and areference signal transmission and a second TPR between an enhancementlayer data transmission and the reference signal transmission; andtransmit signaling to one or more UE indicating the first TPR and secondTPR.

In some aspects of the method, apparatuses, and/or non-transitorycomputer-readable medium of the second set of examples, thedetermination of the first TPR and the second TPR may includedetermining one or more transmission strategy categories fortransmissions between the base station and a UE; determining one or morepair of TPR values for each transmission strategy category, each pair ofTPR values comprising an associated first TPR value for base layer datatransmissions and an associated second TPR value for enhancement layerdata transmissions; and transmitting one or more reference signalsaccording to the determined pair of TPR values. In some examples,signaling may be transmitted that provides the pairs of TPR values andthe transmission strategy category associated with each pair of TPRvalues. Such signaling may be transmitted, for example, via RRCsignaling. In some examples, the transmission strategy category may bedetermined based on spatial layer sharing of a transmission strategy,and a first pair of TPR values is associated with transmissionstrategies that use spatial layer sharing and a second pair of TPRvalues is associated with transmission strategies that do not usespatial layer sharing.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description, and not as a definition of the limits ofthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presentinvention may be realized by reference to the following drawings. In theappended figures, similar components or features may have the samereference label. Further, various components of the same type may bedistinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

FIG. 1A illustrates an example of a wireless communications system, inaccordance with various aspects of the disclosure;

FIG. 1B illustrates a hierarchical modulation environment in accordancewith various aspects of the present disclosure;

FIG. 2 shows a message flow between a base station and a UE, inaccordance with various aspects of the present disclosure;

FIG. 3 shows another message flow between a base station and a UE, inaccordance with various aspects of the present disclosure;

FIGS. 4A-4C show example diagrams of non-orthogonal transmissions, inaccordance with various aspects of the present disclosure;

FIG. 5 shows a block diagram of an apparatus for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 6 shows a block diagram of another apparatus for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 7 shows a block diagram of another apparatus for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 8 shows a block diagram of another apparatus for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 9 shows a block diagram of a UE for use in wireless communication,in accordance with various aspects of the present disclosure;

FIG. 10 shows a block diagram of a base station (e.g., a base stationforming part or all of an eNB) for use in wireless communication, inaccordance with various aspects of the present disclosure;

FIG. 11 is a block diagram of a MIMO communication system including abase station and a UE, in accordance with various aspects of the presentdisclosure;

FIG. 12 is a flow chart illustrating an example of a method for wirelesscommunication, in accordance with various aspects of the presentdisclosure; and

FIG. 13 is a flow chart illustrating an example of another method forwireless communication, in accordance with various aspects of thepresent disclosure.

DETAILED DESCRIPTION

Techniques are described for reference signal transmissions and transmitpower ratio determination in non-orthogonal transmissions. In someexamples, a base station (e.g., a base station including an enhancedNode B (eNB)) and/or a UE may be configured to transmit and/or receivenon-orthogonal transmissions within a wireless communication system. Forexample, the eNB and UE may transmit and/or receive data streams via abase layer of a signal as well as via an enhancement layer that ismodulated on the signal along with the base layer. Thus, concurrent,non-orthogonal, data streams may be provided to the same or differentUEs, and each modulation layer may be used to transmit content that maybe selected based on particular deployments and/or channel conditions.Such concurrent, non-orthogonal data streams may be referred to asnon-orthogonal multiple access (NOMA) transmissions, and in the case ofdownlink transmissions, NOMA transmissions may be referred to as NOMAdownlink transmissions. Various interference mitigation techniques maybe implemented to compensate for interfering signals received fromwithin a cell.

In some examples, NOMA downlink transmissions may be provided to one ormore UEs from a base station through hierarchical and/or superpositionmodulation, in which a first data stream may be modulated fortransmission on a base layer of a signal and a second data stream may bemodulated for transmission on an enhancement layer of the signal. Forexample, the enhancement layer may be superpositioned on the base layerof the signal and the signal may be transmitted to the one or more UEs.Additionally or alternatively, the modulation of the first data streamonto the base layer and the second data stream onto the enhancementlayer may be hierarchical, in which a symbol constellation of thetransmitted signal includes sub-constellations associated with the baselayer and enhancement layer. In some examples, a UE may transmitmultiple hierarchical and/or superposition modulation layers to a basestation in a similar manner.

For a UE to which the first data stream is directed, the enhancementlayer may be seen as interference. However, the signal-to-noise ratio(SNR) of the base layer may be at a level that allows successfuldemodulation and decoding of the first data stream from the base layereven in the presence of interference from the enhancement layer. A UE towhich the second data stream is directed may demodulate and/or decodesymbols and/or data received on the base layer, and then performinterference cancellation to cancel the signal of the base layer. The UEmay then demodulate and decode the second data stream from the remainingsignal after interference cancellation. When multiple layers in NOMAdownlink transmissions share some or all of the same resources (e.g.,have partially or fully overlapping resource blocks), a UE may performan interference cancellation operation on one or more of the layers ofthe NOMA downlink transmissions, to identify and decode data streams onother layers that are intended for the UE.

To perform an interference cancellation operation on NOMA downlinktransmissions, a UE may need to estimate channel conditions for thewireless transmission channel used for the downlink transmissions. Suchchannel conditions may be estimated based at least in part on one ormore reference signals transmitted by a base station. In some examples,a traffic-to-pilot power ratio (TPR) may be determined for a base layerfor a non-orthogonal channel and another TPR may be determined for anenhancement layer for the non-orthogonal channel. Reference signaltransmissions may be transmitted by a base station at a reference signaltransmission power, and the UE may estimate channel quality for the baselayer or the enhancement layer based at least in part on an energy levelof the received reference signal and one or more of the first TPR or thesecond TPR. Interference cancelation may be performed on the receivedsignals in order to cancel out interference from other modulationlayers.

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the spirit and scope of the disclosure. Various examplesmay omit, substitute, or add various procedures or components asappropriate. For instance, the methods described may be performed in anorder different from that described, and various steps may be added,omitted, or combined. Also, features described with respect to someexamples may be combined in other examples.

FIG. 1A shows a block diagram of a wireless communication system 100, inaccordance with various aspects of the present disclosure. The wirelesscommunication system 100 may include a plurality of base stations 105(e.g., base stations forming parts or all of one or more eNBs), a numberof UEs 115, and a core network 130. Some of the base stations 105 maycommunicate with the UEs 115 under the control of a base stationcontroller (not shown), which may be part of the core network 130 orcertain ones of the base stations 105 in various examples. Some of thebase stations 105 may communicate control information and/or user datawith the core network 130 through backhaul links 132. In some examples,some of the base stations 105 may communicate, either directly orindirectly, with each other over backhaul links 134, which may be wiredor wireless communication links. The wireless communication system 100may support operation on multiple carriers (waveform signals ofdifferent frequencies). Multi-carrier transmitters can transmitmodulated signals simultaneously on the multiple carriers. For example,each communication link 125 may be a multi-carrier signal modulatedaccording to various radio technologies. Each modulated signal may besent on a different carrier and may carry control information (e.g.,reference signals, control channels, etc.), overhead information, data,etc.

The base stations 105 may wirelessly communicate with the UEs 115 viaone or more base station antennas. Each of the base stations 105 mayprovide communication coverage for a respective coverage area 110. Insome examples, a base station 105 may be referred to as an access point,a base transceiver station (BTS), a radio base station, a radiotransceiver, a basic service set (BSS), an extended service set (ESS), aNodeB, an evolved NodeB (eNB), a Home NodeB, a Home eNodeB, or someother suitable terminology. The coverage area 110 for a base station 105may be divided into sectors making up just a portion of the coveragearea. The wireless communication system 100 may include base stations105 of different types (e.g., macro, micro, and/or pico base stations).The base stations 105 may also utilize different radio technologies,such as cellular and/or WLAN radio access technologies. The basestations 105 may be associated with the same or different accessnetworks or operator deployments (e.g., collectively referred to hereinas “operators”). The coverage areas of different base stations 105,including the coverage areas of the same or different types of basestations 105, utilizing the same or different radio technologies, and/orbelonging to the same or different access networks, may overlap.

In some examples, the wireless communication system 100 may include anLTE/LTE-A communication system (or network). In LTE/LTE-A communicationsystems, the term evolved NodeB or eNB may be, for example, used todescribe ones or groups of the base stations 105. In some examples, thewireless communication system 100 may include an LTE/LTE-A communicationsystem that supports hierarchical and/or superposition modulation andinterference cancellation, such as an LTE/LTE-A communication systemthat supports the transmission of a set of NOMA downlink transmissions.In some examples, the wireless communication system 100 may supportwireless communication using one or more access technologies differentfrom LTE/LTE-A.

The wireless communication system 100 may be or include a HeterogeneousLTE/LTE-A network in which different types of base stations 105 providecoverage for various geographical regions. For example, each basestation 105 may provide communication coverage for a macro cell, a picocell, a femto cell, and/or other type of cell. Small cells such as picocells, femto cells, and/or other types of cells may include low powernodes or LPNs. A macro cell, for example, covers a relatively largegeographic area (e.g., several kilometers in radius) and may allowunrestricted access by UEs with service subscriptions with the networkprovider. A pico cell would, for example, cover a relatively smallergeographic area and may allow unrestricted access by UEs with servicesubscriptions with the network provider. A femto cell would also, forexample, cover a relatively small geographic area (e.g., a home) and, inaddition to unrestricted access, may also provide restricted access byUEs having an association with the femto cell (e.g., UEs in a closedsubscriber group (CSG), UEs for users in the home, and the like). An eNBfor a macro cell may be referred to as a macro eNB. An eNB for a picocell may be referred to as a pico eNB. And, an eNB for a femto cell maybe referred to as a femto eNB or a home eNB. An eNB may support one ormultiple (e.g., two, three, four, and the like) cells.

The core network 130 may communicate with the base stations 105 via abackhaul link 132 (e.g., S1 application protocol, etc.). The basestations 105 may also communicate with one another, e.g., directly orindirectly via backhaul links 134 (e.g., ×2 application protocol, etc.)and/or via backhaul links 132 (e.g., through core network 130). Thewireless communication system 100 may support synchronous orasynchronous operation. For synchronous operation, the eNBs may havesimilar frame and/or gating timing, and transmissions from differenteNBs may be approximately aligned in time. For asynchronous operation,the eNBs may have different frame and/or gating timing, andtransmissions from different eNBs may not be aligned in time.

The UEs 115 may be dispersed throughout the wireless communicationsystem 100. A UE 115 may also be referred to by those skilled in the artas a mobile device, a mobile station, a subscriber station, a mobileunit, a subscriber unit, a wireless unit, a remote unit, a wirelessdevice, a wireless communication device, a remote device, a mobilesubscriber station, an access terminal, a mobile terminal, a wirelessterminal, a remote terminal, a handset, a user agent, a mobile client, aclient, or some other suitable terminology. A UE 115 may be a cellularphone, a personal digital assistant (PDA), a wireless modem, a wirelesscommunication device, a handheld device, a tablet computer, a laptopcomputer, a cordless phone, a wearable item such as a watch or glasses,a wireless local loop (WLL) station, etc. A UE 115 may be able tocommunicate with macro eNBs, pico eNBs, femto eNBs, relays, and thelike. A UE 115 may also be able to communicate over different types ofaccess networks, such as cellular or other WWAN access networks, or WLANaccess networks. In some modes of communication with a UE 115,communication may be conducted over a plurality of communication links125 or channels (i.e., component carriers), with each channel using acomponent carrier between the UE 115 and one of a number of cells (e.g.,serving cells, which cells may in some cases be operated by the same ordifferent base stations 105).

The communication links 125 shown in wireless communication system 100may include uplink channels (using component carriers) for carryinguplink (UL) communications (e.g., transmissions from a UE 115 to a basestation 105) and/or downlink channels (using component carriers) forcarrying downlink (DL) communications (e.g., transmissions from a basestation 105 to a UE 115). The UL communications or transmissions mayalso be called reverse link communications or transmissions, while theDL communications or transmissions may also be called forward linkcommunications or transmissions. In some examples, one or more downlinkchannels may carry NOMA downlink transmissions.

In embodiments, the components of wireless communication system 100including the eNBs 105 and/or UEs 115 are configured for feedback anddecoding of non-orthogonal channels including transmit power ratiodetermination for multiple modulation layers of non-orthogonaltransmissions. As used herein, “non-orthogonal channels” includeschannels of a carrier between a multiple-antenna transmitter and amultiple-antenna receiver for possible transmission layers includingboth orthogonal and non-orthogonal layers. For example, non-orthogonalchannels for a carrier may include channels for transmission techniquessuch as SU-MIMO, MU-MIMO, and/or NOMA.

In some examples, channel feedback for a non-orthogonal channel may beestimated based at least in part on one or more reference signalstransmitted by a base station and one or more TPR pairs associated withpotential TSs for transmissions over the non-orthogonal channel. Forexample, a first TPR may be determined for a base layer for anon-orthogonal channel and a second TPR may be determined for anenhancement layer for the non-orthogonal channel. Reference signaltransmissions may be transmitted by a base station at a reference signaltransmission power, and a UE may estimate channel quality for the baselayer or the enhancement layer based at least in part on an energy levelof the received reference signal and one or more of the first TPR or thesecond TPR. A base station may, in certain examples, transmit TPRsignaling that may indicate one or more TPR values for one or both ofthe base layer or enhancement layer. FIG. 2 provides an example of how aTPR determination may be used to facilitate channel estimation by a UE.

As mentioned above, various aspects of the present disclosure aredirected to transmissions on multiple hierarchical and/or superpositionmodulation layers. FIG. 1B illustrates a system 100-a in which a basestation 105-a may communicate with one or more UEs 115 usinghierarchical modulation. System 100-a may illustrate, for example,aspects of wireless communication system 100 illustrated in FIG. 1A. Inthe example of FIG. 1B, a base station 105-a may communicate with anumber of UEs 115-a, 115-b, and 115-c within a coverage area 110-a ofthe base station 105-a. In this example, multiple modulation layers maybe employed for wireless communications, which may include a base layerand one or more enhancement layers concurrently transmitted between thebase station 105-a and the UEs 115. The base layer, according to someexamples, may provide transmissions having relatively high reliabilitycommunications between the base station 105-a and UEs 115, resulting ina higher likelihood that the UEs 115 within the coverage area 110-a willbe able to decode content transmitted on the base modulation layer. Theenhancement layer, according to various examples, may provide relativelylower reliability communications between the base station 105-a and UEs115 as compared to the base layer. As such, transmissions on theenhancement layer, in order to have reliable reception and decoding, maybe provided to UEs 115 having relatively good channel conditions.

As mentioned, the enhancement layer may have a lower likelihood ofsuccessful reception relative to the base layer, with the likelihood ofsuccessful reception largely dependent upon channel conditions betweenthe base station 105-a and UEs 115. In some deployments, such asillustrated in FIG. 1B, UEs 115-a and 115-b may be located relativelyclose to base station 105-a in area 155, while UE 115-c may be locatedcloser to a cell edge of the base station 105-a coverage area 110-a. Ifit is determined that UEs 115-a and 115-b located in area 155 havechannel conditions conducive for hierarchical and/or superpositionmodulation, base station 105-a may signal to the UEs 115-a and 115-bthat such communications may be employed. In such cases, communicationlinks 125-a may include both a base layer and an enhancement layer, andUEs 115-a and 115-b may support communications on each of the modulationlayers. In this example, UE 115-c, located closer to the cell edge ofcoverage area 110-a, and outside of area 155, may be signaled tocommunicate using only the base layer in communications link 125-b.While the communications link 125-b may still be transmitted with boththe base and enhancement layers, UE 115-c may not attempt to decode theenhancement layer due to the relatively low likelihood of successfulreception and decoding of content modulated on the enhancement layer. Inother examples, one or more of the UEs 115 may not have the capabilityto receive and decode enhancement layer transmissions, in which case thebase layer is simply received and decoded according to establishedtechniques.

FIG. 2 shows a message flow 200 between a base station 205 and a UE 215,in accordance with various aspects of the present disclosure. In someexamples, the base station 205 may be an example of aspects of one ormore of the base stations 105 described with reference to FIG. 1A orFIG. 1B. In some examples, the UE 215 may be an example of aspects ofone or more of the UEs 115 described with reference to FIG. 1A or FIG.1B. Messages may be transmitted between the base station 205 and the UE215 over at least one radio frequency spectrum band.

As shown in FIG. 2, the base station 205 may transmit TPR signaling 220to the UE 215. The TPR signaling may indicate a TPR for base layertransmissions, enhancement layer transmissions, or both. In legacysystems, a common (or cell-specific) reference signal (CRS) or channelstate information reference signal (CSI-RS) may be used for channelquality information estimation, with TPR signaled through radio resourcecontrol (RRC) signaling. TPR changes in such systems may be relativelyslow, and such signaling would provide information on TPR for a solelegacy modulation layer. According to various aspects of the presentdisclosure, multiple hierarchical and/or superposition modulation layersmay be provided, as mentioned above. The total power transmitted by abase station for NOMA downlink transmissions is split between base layertransmissions and enhancement layer transmissions, and thus the TPRsignaled through legacy RRC signaling may not be sufficient to indicateTPR for all of the hierarchical and/or superposition modulation layers.

According to various aspects of the disclosure, TPR information for thebase layer and enhancement layer may be included in the TPR signaling220. In some examples, the TPR signaling 220 may be transmitted usingRRC signaling to signal TPR for the base layer and enhancement layer,respectively. The TPR for each modulation layer may be indicated as aratio with respect to, for example, CRS or CSI-RS transmissions. In someexamples, the total of the TPRs for each modulation layer does not needto be 0 dB. For example, the TPR may be −2.0 dB for base layertransmissions, and −3.0 dB for enhancement layer transmissions,according to one transmit strategy (TS), and may be other values fordifferent TSs.

In some examples, TPR pairs may be signaled for one or more differentTSs. In certain examples, due to the number of available TSs, ratherthan provide signaling for each TS, the TPR signaling 220 may includeone or more TPR pairs that apply to different categories of TS. Forexample, a first TPR pair may include a base layer TPR and anenhancement layer TPR for TSs with spatial layer sharing, and a secondTPR pair may include different base and enhancement layer TPRs for TSswithout spatial layer sharing. In one example, a base layer may betransmitted using a transmit power of 80% of the total power, and anassociated enhancement layer may be transmitted using a transmit powerof 20% of the total power (i.e., a TPR pair of 0.8, 0.2) for TSs withspatial layer sharing, and a different TPR pair of 0.5, 0.5 may be usedfor TSs without spatial layer sharing. Of course, numerous different TPRpairs may be utilized as will be readily apparent to one of skill in theart. In some examples, a default pair of TPRs may be provided for two ormore different TSs. In other examples, multiple TPR pairs may beprovided for each TS category, and a UE receiving reference signals mayprovide channel information feedback reports for each different TPR pairfor each TS.

With continued reference to FIG. 2, the UE 215 may perform receiving andprocessing of the TPR signaling 220, as indicated at block 225. The UE215 may then determine the TPR for each of the base layer andenhancement layer transmissions, as indicated at block 230. The basestation 205 may transmit reference signal transmissions 235 (e.g., CRSor CSI-RS). At the UE 215, the determined TPR for the base andenhancement layers may be used in SNR prediction and for generating achannel quality indicator (CQI) for transmissions using the base layerand/or enhancement layer over the non-orthogonal channel, as indicatedat block 240. The UE 215 may transmit a channel feedback report 245,which may include all or part of the CQI, to the base station 205. Thebase station 205 may perform scheduling of NOMA transmissions based atleast in part on the channel feedback report 245 from the UE 215, asindicated at block 250. In some examples, the base station 205 mayschedule groups of multiple UEs to receive transmissions on one or moreof the base layer and enhancement layer, with UEs within a group allsharing the same TPR pair in order to avoid a SNR mismatch among UEs andpotential performance loss.

At some point in time following scheduling of NOMA transmissions 250(and in some examples, immediately following), the base station 205 maytransmit NOMA downlink transmissions 255. The NOMA downlinktransmissions 255 may be received by the UE 215 (and possibly other UEsin a NOMA group). In some cases, NOMA downlink transmission 255 mayinclude a DM-RS, which may be used by the UE 215 to support thedemodulation of the base layer and/or enhancement layer.

At block 260 the UE 215 may perform an interference cancellationoperation (e.g., a codeword-level interference cancellation (CWIC)operation, a symbol-level interference cancellation (SLIC) operation,etc.) on the interfering transmission (e.g., base layer). Theinterference cancellation operation may be performed on an interferingtransmission based at least in part on CQI information for the baselayer and enhancement layer and/or DM-RS of the transmission. In someexamples, the interference cancellation operation may include decoding(e.g., CRC-descrambling) an interfering transmission (e.g., ahierarchical and/or superposition modulation layer) corresponding tocommunications for a different UE (not shown) or corresponding to one ofmultiple hierarchical and/or superposition modulation layers for the UE215. For example, the UE 215 may be scheduled to receive enhancementlayer transmissions only, or may be scheduled to receive both base layerand enhancement layer transmissions, and may perform interferencecancelation on the base layer to identify and decode the data streammodulated on the enhancement layer of the received signal.

At block 265, the UE 215 may perform the demodulation of the base layerand/or the enhancement layer based on the DM-RS of the data transmissionreceived over the non-orthogonal channel and the determined TPR for thebase and enhancement layers. For example, the UE 215 may receive theDM-RS of the data transmission over the non-orthogonal channel anddetermine signal reference values (e.g., phase, amplitude, etc.) fordemodulation of the data transmission based on the TPR values. Blocks265 and 260 may be performed iteratively (e.g., demodulation of baselayer prior to interference cancellation of base layer and demodulationof enhancement layer from the signal after interference cancellation,etc.).

FIG. 3 shows a message flow 300 between a base station 305 and a UE 315in accordance with various aspects of the present disclosure. In someexamples, the base station 305 may be an example of aspects of one ormore of the base stations 105 described with reference to FIG. 1A orFIG. 1B. In some examples, the UE 315 may be an example of aspects ofone or more of the UEs 115 described with reference to FIG. 1A or FIG.1B. In some examples, the UE 315, and in some examples other UEs (notshown), may receive NOMA communications (e.g., communications on one ormore of a base layer or enhancement layer). Messages may be transmittedbetween the base station 305 and the UE 315 over at least one radiofrequency spectrum band.

As shown in FIG. 3, the base station 305 may transmit TPR signaling 320to the UE 315. The TPR signaling may indicate a TPR for base layertransmissions, enhancement layer transmissions, or both. In someexamples, the TPR signaling 320 may be transmitted using RRC signalingto signal TPR for the base layer and enhancement layer, respectively. Insome examples, the TPR signaling 320 may include one or more pairs ofTPRs, with one value of the TPR pair corresponding to a base layer TPRand a second value of the TPR pair corresponding to an enhancement layerTPR. The TPR for each modulation layer may be indicated as a ratio withrespect to, for example, CRS or CSI-RS transmissions. The UE 315 mayperform receiving and processing of the TPR signaling 320, as indicatedat block 325. The UE 315 may then determine the TS category for downlinktransmissions, as indicated at block 330.

At block 335, the UE 315 may determine a TPR pair for base layer andenhancement layer transmissions based on the determined TS category. Insome examples, TPR pairs may be signaled in the TPR signaling 320 forone or more different categories of TSs. For example, a first TPR pairmay include a base layer TPR and an enhancement layer TPR for TSs withspatial layer sharing, and a second TPR pair may include different baseand enhancement layer TPRs for TSs without spatial layer sharing. The UE315 may determine the TS category, in some examples, based oninformation that may be included in downlink control information (DCI)that may be received on a physical downlink control channel (PDCCH). Insome examples, UE 315 may determine a precoding matrix indicator (PMI)and information on spatial layer usage from the DCI received on thePDCCH. In certain examples, one or more PDCCH transmissions may includea TPR field. Such a TPR field may allow one or more TPR values tochange, and may allow base station 305 to overwrite a TPR that may havebeen provided in, for example, RRC signaling in the TPR signaling 320.In some situations, two or more TSs may exist that have the same spatiallayer usage.

The TPR for such different TSs may be set to be the same value, to avoidambiguity in what TPR values are to be used by a UE 315, according tocertain examples. In other examples, different TSs that have the samespatial layer usage may have different TPR values based on whether datainterference cancellation is used for the associated transmissions. Insuch examples, the TPR for use by UE 315 may be resolved based on aninterference cancellation flag that may be included in the PDCCHtransmissions. For example, an interference cancellation flag that isset to a value of one may indicate data interference cancellation is tobe used and may imply a first TPR pair, and an interference cancellationflag that is cleared to a value of zero may indicate that datainterference cancellation is not used and may imply a second TPR pair.Then given the PDCCH transmissions, the TPR is known after the UEdetermines which TS is being used, and channel and interferencestatistics may be properly constructed.

With continued reference to FIG. 3, the base station 305 may transmitreference signal transmissions 340 (e.g., CRS or CSI-RS). At the UE 315,the determined TPR pair may be used in SNR prediction and for estimatingchannel quality for one or more of the base layer and enhancement layerbased on an energy level of the received reference signal and thedetermined TPR pair, as indicated at block 345. The UE 315 may transmita channel feedback report 350, which may include all or part of theestimated channel quality (e.g., in a CQI report, etc.), to the basestation 305.

The base station 305 may perform scheduling of non-orthogonaltransmissions based at least in part on the channel feedback report 350from the UE 315, as indicated at block 355. For example, the basestation 305 may schedule groups of multiple UEs to receive data streamsvia one or more base layers and/or enhancement layers of datatransmissions, with UEs within a group all sharing the same TPR pair inorder to avoid an SNR mismatch among UEs, which may result inperformance loss. The base station 305 may then transmit non-orthogonaldownlink transmissions 360. The non-orthogonal downlink transmissions360 may be received by the UE 315 (and possibly other UEs in a group).The non-orthogonal downlink transmission 360 may include a DM-RS, andmay be used by the UE 315 for the demodulation of the base layer or theenhancement layer.

At block 365, the UE 315 operations may include performing aninterference cancellation operation (e.g., CWIC, SLIC, etc.) on aninterfering transmission. The interference cancellation operation may beperformed on an interfering transmission based at least in part on CQIinformation for the base layer and enhancement layer. In some examples,the interference cancellation operation may include decoding (e.g.,CRC-descrambling) an interfering transmission (e.g., a hierarchicaland/or superposition modulation layer) corresponding to communicationsfor a different UE (not shown) or corresponding to one of multiplehierarchical and/or superposition modulation layers for the UE 315. Forexample, the UE 315 may be scheduled to receive enhancement layertransmissions only, or may be scheduled to receive both base layer andenhancement layer transmissions, and may perform interferencecancelation on the base layer to identify and decode the data streammodulated on the enhancement layer of the received signal.

At block 370, the UE 315 may perform the demodulation of the base layerand/or the enhancement layer based on the received DM-RS included in thenon-orthogonal downlink transmission 360 and the determined TPR for thebase and enhancement layers. For example, the UE 315 may receive theDM-RS of the data transmission over the non-orthogonal channel anddetermine reference values (e.g., phase, amplitude, etc.) fordemodulation of the data transmission based on the TPR values. Blocks370 and 365 may be performed iteratively (e.g., demodulation of baselayer prior to interference cancellation of base layer and demodulationof enhancement layer from the signal after interference cancellation,etc.).

FIGS. 4A-4C show example diagrams of TPR for DM-RS for non-orthogonaltransmissions, in accordance with various aspects of the presentdisclosure. Diagram 400-a of FIG. 4A illustrates signaling power levelsfor a NOMA transmission 405-a. The NOMA transmission 405-a includes CRS410-a, DM-RS 420-a, a base layer 430-a, and an enhancement layer 435-a.The TPR for DM-RS 420-a (e.g., relative to CRS 410-a) may be the totalof a TPR pair for the base layer 430-a and the enhancement layer 435-a,according to some examples. For example, if a TPR pair has values of 0.8and 0.3 for base layer 430-a and enhancement layer 435-a relative to CRS410-a, the DM-RS 420-a TPR may be determined to be the total of the TPRpair, or 1.1. The TPR for data transmissions (e.g., base layer 430-a orenhancement layer 435-a) may be determined with respect to a transmitpower level of CRS 410-a. As mentioned above, one or more TPR valuesprovided in TPR signaling may be overwritten by new TPR values in PDCCHtransmissions associated with NOMA transmission 405-1. In examples wherethe DM-RS 420-b TPR is the total of the TPR pair for data transmissions,the TPR for DM-RS 420-b may be dynamically updated based on the new TPRvalues.

Diagram 400-b of FIG. 4B illustrates signaling power levels for a NOMAtransmission 405-b. The NOMA transmission 405-b includes CRS 410-b,DM-RS 420-b, a base layer 430-b, and an enhancement layer 435-b. ForNOMA transmission 405-b, TPR for DM-RS 420-b (e.g., relative to CRS410-b) may be independent of the TPR pair for base layer 430-b andenhancement layer 435-b. For example, a power level for the DM-RS 420-bmay be the same as (or a predetermined factor of) the power level forCRS 410-b. Thus, if the TPR pair for base layer 430-b and enhancementlayer 435-b transmit powers have values of 0.8 and 0.3 relative to CRS410-b, the DM-RS 420-b TPR may be determined to be 1.0 (e.g., to have aunity power ratio with the CRS 410-b transmissions). As mentioned above,one or more TPR values provided in TPR signaling may be overwritten bynew TPR values in PDCCH transmissions associated with NOMA transmission405-b. In examples where the DM-RS 420-b TPR is determined to be unitywith the CRS 410-b power, the new TPR values may not affect the DM-RS420-b power level relative to the CRS 410-b power level.

Diagram 400-c of FIG. 4C illustrates signaling power levels for a NOMAtransmission 405-c. The NOMA transmission 405-c includes CRS 410-c, afirst DM-RS[0] 420-c transmitted via a first antenna port, a secondDM-RS[1] 425-c transmitted via a second antenna port, a base layer430-c, and an enhancement layer 435-c. In some cases, the TPR for thefirst DM-RS[0] 420-c (e.g., relative to CRS 410-c) may correspond to theTPR of the base layer 430-c, and the TPR for the second DM-RS[1] (e.g.,relative to CRS 410-c) may correspond to the TPR of the enhancementlayer 435-c. The first and second antenna ports may be selected based onwhether a UE is to receive base layer transmissions or enhancement layertransmission, and the TPR for the base layer 430-c or the TPR for theenhancement layer 435-c may correspond to the antenna port based on thisselection. In such examples, different UEs, may be included in a groupof UEs for NOMA transmissions, and each UE within the group may beprovided with its own antenna port for NOMA transmissions with acorresponding DM-RS. For example, one UE may be assigned antenna port 7and another UE may be assigned antenna port 8. In such cases, a TPR fordata resource elements in the NOMA transmission may be the same as theTPR for the corresponding DM-RS[0] 420-c or DM-RS[1] 425-c (e.g., thedifference between the DM-RS power level and data resource element powerlevel of the NOMA transmission may be 0 dB), and no TPR field isnecessary in PDCCH transmissions, even if the TPR value used for thetransmission is different than what was signaled in the TPR signaling,because of the identified antenna port and no other UE potentiallysharing a DM-RS transmission.

In some examples, the NOMA transmissions 405 shown in FIGS. 4A-4C mayalso include other reference signals (e.g., CSI-RS, etc.) which may betransmitted at a normalized power level to CRSs 410.

FIG. 5 shows a block diagram 500 of an apparatus 515 for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure. In some examples, the apparatus 515 may be an example ofaspects of one or more of the UEs 115, 215, or 315 described withreference to FIG. 1A, 1B, 2, 3, or 4A-4C. The apparatus 515 may also bea processor. The apparatus 515 may include a receiver 510, a wirelesscommunication manager 520, and/or a transmitter 530. Each of thesecomponents may be in communication with each other.

The components of the apparatus 515 may, individually or collectively,be implemented using one or more Application-Specific IntegratedCircuits (ASICs) adapted to perform some or all of the applicablefunctions in hardware. Alternatively, the functions may be performed byone or more other processing units (or cores), on one or more integratedcircuits. In other examples, other types of integrated circuits may beused (e.g., Structured/Platform ASICs, Field Programmable Gate Arrays(FPGAs), and other Semi-Custom ICs), which may be programmed in anymanner known in the art. The functions of each unit may also beimplemented, in whole or in part, with instructions embodied in amemory, formatted to be executed by one or more general orapplication-specific processors.

In some examples, the receiver 510 may include at least one radiofrequency (RF) receiver, such as at least one RF receiver operable toreceive transmissions over at least one radio frequency spectrum band.In some examples, the at least one radio frequency spectrum band may beused for wireless communications, as described, for example, withreference to one or more of FIG. 1A, 1B, 2, 3, or 4A-4C. The receiver510 may be used to receive various types of data and/or control signals(i.e., transmissions) over one or more communication links of a wirelesscommunication system, such as one or more communication links of thewireless communication system 100 described with reference to FIG. 1A orFIG. 1B. For example, the receiver 510 may receive TPR signaling such asdiscussed above, and provide TPR signaling 525 to wirelesscommunications manager 520. The receiver 510 may also receive one ormore reference signal transmissions and one or more data signaltransmissions, and provide the transmissions to the wirelesscommunication manager 520.

In some examples, the transmitter 530 may include at least one RFtransmitter, such as at least one RF transmitter operable to transmitover at least one radio frequency spectrum band. The transmitter 530 maybe used to transmit various types of data and/or control signals (i.e.,transmissions) over one or more communication links of a wirelesscommunication system, such as one or more communication links of thewireless communication system 100 described with reference to FIG. 1A orFIG. 1B. For example, the transmitter 530 may receive a channel feedbackreport 535 from wireless communications manager 520, and may transmitthe channel feedback report to a base station.

The wireless communication manager 520 may be used to manage some or allof the wireless communications to and/or from the apparatus 515. In someexamples, the wireless communication manager 520 may include a TPRprocessor 540 and a channel quality estimator 550.

In some examples, the TPR processor 540 may be used to receive TPRsignaling information for a UE (e.g., a UE including the apparatus 515).The TPR processor 540, in some examples, may determine a first TPR for abase layer for a non-orthogonal channel and a second TPR for anenhancement layer for the non-orthogonal channel. Such a determinationmay be based, at least in part, on TPR signaling 525 received from abase station, according to certain examples.

In some examples, the channel quality estimator 550 may be used toestimate, based at least in part on TPR information 555 received fromthe TPR processor 540, channel quality for inclusion in a channelfeedback report that may be provided to a base station. In someexamples, the receiver 510 may provide the channel quality estimator 550with at least a portion of a reference signal 526 of the non-orthogonalchannel, and the channel quality estimator 550 may estimate channelquality for the base layer or the enhancement layer based at least inpart on an energy level of the received reference signal 526 and the TPRinformation 555 received from the TPR processor 540.

FIG. 6 shows a block diagram 600 of a wireless communication manager520-a for use in wireless communication, in accordance with variousaspects of the present disclosure. In some examples, the wirelesscommunication manager 520-a may be an example of aspects of the wirelesscommunication manager 520 of FIG. 5 and may be coupled with a receiver510 and/or transmitter 530, in some cases. The wireless communicationmanager 520-a may also be a processor.

The components of the wireless communication manager 520-a may,individually or collectively, be implemented using one or more ASICsadapted to perform some or all of the applicable functions in hardware.Alternatively, the functions may be performed by one or more otherprocessing units (or cores), on one or more integrated circuits. Inother examples, other types of integrated circuits may be used (e.g.,Structured/Platform ASICs, FPGAs, and other Semi-Custom ICs), which maybe programmed in any manner known in the art. The functions of each unitmay also be implemented, in whole or in part, with instructions embodiedin a memory, formatted to be executed by one or more general orapplication-specific processors.

The wireless communication manager 520-a may be used to manage some orall of the wireless communications to and/or from one or more of the UEs115, 215, 315 described with reference to FIG. 1A, 1B, 2, 3 or 4A-4C. Insome examples, the wireless communication manager 520-a may include aTPR processor 540-a, a channel quality estimator 550-a, a referencesignal processor 660, and a NOMA transmission processor 670.

In some examples, the TPR processor 540-a may be used to receive TPRsignaling 625 for a UE (e.g., a UE including the wireless communicationmanager 520-a). The TPR processor 540-a, in some examples, may determinea first TPR for a base layer for a non-orthogonal channel and a secondTPR for an enhancement layer for the non-orthogonal channel. Such adetermination may be based, at least in part, on TPR signaling 625received from a base station via a receiver, according to certainexamples.

In some examples, the TPR processor 540-a may include a TS categoryprocessor 645 that may determine which of one or more TS categories isto be used for downlink transmissions from a base station to the UE overthe non-orthogonal channel. In some examples, the determination of theone or more TS categories may be based at least in part on spatial layersharing of respective TSs. For example, a first pair of TPR values maybe associated with TSs that use spatial layer sharing and a second pairof TPR values may be associated with TSs that do not use spatial layersharing. Information related to the TS category may be provided to TPRprocessor 540-a, which may select the first TPR and the second TPR fromat least one pair of first TPR and second TPR values, each pairassociated with one of the TS categories. In some examples, the TPRprocessor 540-a may receive TPR signaling 625 and/or other configurationinformation, via the receiver, from a base station that provides the oneor more pairs of first TPR and second TPR values and the TS categoryassociated with each of the pairs of TPR values. Such signaling may bereceived, for example, via RRC messaging.

In some examples, the first TPR and the second TPR may be determinedbased at least in part on information contained in one or more PDCCHtransmissions, such as in one or more DCI transmissions, for example.The information contained in the one or more PDCCH transmission mayinclude, according to various examples, one or more of precoding matrixinformation, spatial layer sharing information, TPR information, orinterference cancellation information. In some examples, theinterference cancellation information may include an interferencecancellation flag, and a first pair of TPR values may be selected forthe first TPR and the second TPR when the flag is set, and a second pairof TPR values may be selected for the first TPR and the second TPR whenthe flag is cleared. In some examples, the TPR processor 540-a may beprovided with two or more pairs of TPR values via, for example, RRCmessaging received at the receiver, and each pair of TPR values mayinclude an associated first TPR value and second TPR value. In furtherexamples, the TPR signaling 625 received at the TPR processor 540-a mayinclude an indication of which pair of TPR values are to be selected forthe first TPR and the second TPR.

In some examples, the reference signal processor 660 may receive (e.g.,via a receiver), one or more reference signals 635. Such referencesignals 635 may include CRS, CSI-RS, and/or DM-RS, for example. In someexamples, the channel quality estimator 550-a may receive TPRinformation 655 from the TPR processor 540-a, where the TPR information655 may include an indication of the first TPR and second TPR, andestimate channel quality for the base layer or the enhancement layerbased on an energy level of the received reference signal 635 and one ormore of the first TPR or the second TPR. The channel quality estimationmay be included in a channel feedback report 652 that may be transmitted(e.g., via a transmitter) to a base station. In examples in which thereference signals 635 include a DM-RS, the reference signal processor660 may determine demodulation information 685 (e.g., phase reference,amplitude reference, etc.) for use by NOMA transmission processor 670 indemodulating a data transmission based at least in part on a TPR valuefor the received DM-RS.

In some cases, the reference signal processor 660 may receive TPRinformation 655 from the TPR processor 540-a, where the TPR information655 may include an indication of the first TPR and the second TPR. Inexamples in which the reference signals 635 include a DM-RS, the TPRvalue for the received DM-RS may be a sum of the first TPR and thesecond TPR. In other examples, the TPR value for the received DM-RS maybe independent of one or more of the first TPR or second TPR, and maybe, for example, a unity ratio (e.g., the DM-RS may have the same powerlevel as the CRS or CSI-RS, etc.). In some examples, the DM-RS may beassociated with one of a number of available antenna ports, and theantenna port selected for estimating the channel quality may bedetermined based on whether base layer transmissions or enhancementlayer transmissions are to be received. Furthermore, in some examples, atransmit power for data transmissions for the base layer transmissionsor enhancement layer transmissions may correspond to the transmit powerof the DM-RS of the associated base layer or enhancement layer.

In some examples, the NOMA transmission processor 670 may receive NOMAdownlink transmissions 672 via a receiver, and may also receive CQIinformation 686 from the channel quality estimator 550-a. The NOMAtransmission processor 670 may include an interference cancellationprocessor 675, which may perform an interference cancellation operationon the interfering transmission(s) or layers of NOMA downlinktransmissions 672 based on the demodulation information 685 and/or CQIinformation 686 (e.g., CQI information for the base layer, enhancementlayer, and/or DM-RS of the transmission). In some examples, theinterference cancellation processor 675 may be used to perform aninterference cancellation operation on interfering transmission(s) basedon an interference cancellation flag that may be set in one or morePDCCH transmissions. In some examples, the interference cancellationoperation may include decoding the interfering transmission(s) and thencanceling the interfering transmission(s) from the set of NOMA downlinktransmissions 672.

FIG. 7 shows a block diagram 700 of an apparatus 705 for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure. In some examples, the apparatus 705 may be an example ofaspects of one or more of the base stations 105, 205, or 305 describedwith reference to one or more of FIG. 1A, 1B, 2, 3, or 4A-4C. Theapparatus 705 may also be a processor. The apparatus 705 may include areceiver 710, a NOMA manager 720, and/or a transmitter 730. Each ofthese components may be in communication with each other.

The components of the apparatus 705 may, individually or collectively,be implemented using one or more ASICs adapted to perform some or all ofthe applicable functions in hardware. Alternatively, the functions maybe performed by one or more other processing units (or cores), on one ormore integrated circuits. In other examples, other types of integratedcircuits may be used (e.g., Structured/Platform ASICs, FPGAs, and otherSemi-Custom ICs), which may be programmed in any manner known in theart. The functions of each unit may also be implemented, in whole or inpart, with instructions embodied in a memory, formatted to be executedby one or more general or application-specific processors.

In some examples, the receiver 710 may include at least one RF receiver,such as at least one RF receiver operable to receive transmissions overat least one radio frequency spectrum band. In some examples, the atleast one radio frequency spectrum band may be used for wirelesscommunications, as described, for example, with reference to one or moreof FIG. 1A, 1B, 2, 3, or 4A-4C. The receiver 710 may be used to receivevarious types of data and/or control signals (i.e., transmissions) overone or more communication links of a wireless communication system, suchas one or more communication links of the wireless communication system100 described with reference to FIG. 1A or FIG. 1B. For example, thereceiver 710 may receive data, control, or reference signals from one ormore UEs. In some examples, the NOMA manager 720 may receive channelfeedback reports 725 from the receiver 710, and the NOMA manager 720 mayperform scheduling of NOMA transmissions based at least in part on thechannel feedback reports 725.

In some examples, the transmitter 730 may include at least one RFtransmitter, such as at least one RF transmitter operable to transmitover at least one radio frequency spectrum band. The transmitter 730 maybe used to transmit various types of data and/or control signals (i.e.,transmissions) over one or more communication links of a wirelesscommunication system, such as one or more communication links of thewireless communication system 100 described with reference to FIG. 1A orFIG. 1B. For example, the transmitter 730 may transmit data, control, orreference signals to one or more UEs.

The NOMA manager 720 may be used to manage some or all of thenon-orthogonal wireless communications to and/or from the apparatus 705.In some examples, the NOMA manager 720 may include a TPR determinationprocessor 740 and a TPR signaling processor 750.

In some examples, the TPR determination processor 740 may be used todetermine a first TPR between a base layer data transmission and areference signal transmission and a second TPR between an enhancementlayer data transmission and the reference signal transmission. The TPRdetermination processor 740 may pass one or more TPR pairs 765 fornon-orthogonal transmissions to the TPR signaling processor 750. The TPRsignaling processor 750 may be used to transmit TPR signaling 755 (e.g.,via the transmitter 730), to one or more UEs indicating one or more TPRsof the TPR pairs 765 determined by the TPR determination processor 740.

FIG. 8 shows a block diagram 800 of a NOMA manager 720-a for use inwireless communication, in accordance with various aspects of thepresent disclosure. In some examples, the NOMA manager 720-a may be anexample of aspects of the NOMA manager 720 of FIG. 7 and may be coupledwith a receiver and/or transmitter in some cases. The NOMA manager 720-amay also be a processor.

The components of the NOMA manager 720-a may, individually orcollectively, be implemented using one or more ASICs adapted to performsome or all of the applicable functions in hardware. Alternatively, thefunctions may be performed by one or more other processing units (orcores), on one or more integrated circuits. In other examples, othertypes of integrated circuits may be used (e.g., Structured/PlatformASICs, FPGAs, and other Semi-Custom ICs), which may be programmed in anymanner known in the art. The functions of each unit may also beimplemented, in whole or in part, with instructions embodied in amemory, formatted to be executed by one or more general orapplication-specific processors.

The NOMA manager 720-a may be used to manage some or all of thenon-orthogonal wireless communications to/from one or more of the basestations 105, 205, or 305 described with reference to FIG. 1A, 1B, 2, 3or 4A-4C. In some examples, the NOMA manager 720-a may include a TPRdetermination processor 740-a, a TS determination processor 845, a TPRsignaling processor 750-a, a channel feedback processor 850, and areference signal transmission processor 860. In some cases, channelfeedback processor 850 may receive channel feedback reports 825 from oneor more UEs, which may include all or part of one or more CQI reports.

In some examples, the TPR determination processor 740-a may be used todetermine one or more TPR pairs 765-a for potential NOMA transmissionsto one or more UEs, where each TPR pair includes a first TPR between abase layer and a reference signal and a second TPR between anenhancement layer and the reference signal. The TPR determinationprocessor 740-a may pass the one or more TPR pairs 765-a to the TPRsignaling processor 750-a, which may transmit signaling 855 (e.g., via atransmitter), to the one or more UEs indicating, for example a first TPRand a second TPR for NOMA transmissions over a non-orthogonal channel.The TPR signaling processor 750-a, in certain examples, may be used totransmit signaling 855 that provides TPR pairs 765-a and a transmissionstrategy category 865 associated with each TPR pair 765-a determined bythe TS determination processor 845. The signaling 855, in some examples,may be transmitted via RRC signaling.

In some examples, the TS determination processor 845 may determine oneor more transmission strategy categories 865 for transmissions betweenthe base station and UE. The TPR determination processor 740-a, in suchexamples, may determine one or more pairs of TPR values 835 for eachtransmission strategy category 865, with each pair of TPR values 835comprising an associated first TPR value for base layer datatransmissions and an associated second TPR value for enhancement layerdata transmissions. In certain examples, the transmission strategycategory 865 may be determined based on spatial layer sharing of atransmission strategy. In such examples, a first pair of TPR values maybe associated with transmission strategies that use spatial layersharing and a second pair of TPR values may be associated withtransmission strategies that do not use spatial layer sharing.

In some examples, the reference signal transmission processor 860 may beused to transmit one or more reference signals 870 according to TPRvalues of the TPR pairs 765-a. The reference signals may include, forexample, one or more of a CRS, CSI-RS, or DM-RS.

FIG. 9 shows a block diagram 900 of a UE 915 for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure. The UE 915 may have various configurations and may beincluded or be part of a personal computer (e.g., a laptop computer, anetbook computer, a tablet computer, etc.), a cellular telephone, a PDA,a digital video recorder (DVR), an internet appliance, a gaming console,an e-reader, etc. The UE 915 may, in some examples, have an internalpower supply (not shown), such as a small battery, to facilitate mobileoperation. In some examples, the UE 915 may be an example of aspects ofone or more of the UEs 115, 215, 315, or 415 described with reference toFIG. 1A, 1B, 2, 3, or 4, or aspects of one or more of the apparatus 515described with reference to FIG. 5. The UE 915 may be configured toimplement at least some of the UE and/or apparatus features andfunctions described with reference to one or more of FIG. 1A, 1B, 2, 3,4A-4C, 5, or 6.

The UE 915 may include a UE processor 910, UE memory 920, one or more UEtransceiver(s) 930, one or more UE antenna(s) 940, and/or a UE wirelesscommunication manager 960. Each of these components may be incommunication with each other, directly or indirectly, over one or morebuses 935.

The UE memory 920 may include random access memory (RAM) and/orread-only memory (ROM). The UE memory 920 may store computer-readable,computer-executable code 925 containing instructions that are configuredto, when executed, cause the UE processor 910 to perform variousfunctions described herein related to wireless communication and/orcommunication using NOMA communication techniques. Alternatively, thecode 925 may not be directly executable by the UE processor 910 but beconfigured to cause the UE 915 (e.g., when compiled and executed) toperform various of the functions described herein.

The UE processor 910 may include an intelligent hardware device, e.g., acentral processing unit (CPU), a microcontroller, an ASIC, etc. The UEprocessor 910 may process information received through the UEtransceiver(s) 930 and/or information to be sent to the UEtransceiver(s) 930 for transmission through the UE antenna(s) 940. TheUE processor 910 may handle, alone or in connection with the UE wirelesscommunication manager 960, various aspects of wireless communication forthe UE 915. UE processor 910 may, for example, manage transitions of theUE 915 between an RRC idle state and an RRC connected state, and may bein communication with other components of the UE 915, directly orindirectly, over the one or more buses 935.

The UE transceiver(s) 930 may include a modem configured to modulatepackets and provide the modulated packets to the UE antenna(s) 940 fortransmission, and to demodulate packets received from the UE antenna(s)940. The UE transceiver(s) 930 may, in some examples, be implemented asone or more UE transmitters and one or more separate UE receivers. TheUE transceiver(s) 930 may support communications in the first radiofrequency spectrum band and/or the second radio frequency spectrum band.The UE transceiver(s) 930 may be configured to communicatebi-directionally, via the UE antenna(s) 940, with one or more of thebase stations 105, 205, or 305 described with reference to FIG. 1A, 1B,2, 3, or 4A-4C, or with one or more of the apparatus 705 of FIG. 7.While the UE 915 may include a single UE antenna, there may be examplesin which the UE 915 may include multiple UE antennas 940.

The UE wireless communication manager 960 may be configured to performand/or control some or all of the features and/or functions describedwith reference to one or more of FIG. 1A, 1B, 2, 3, 4A-4C, 5, or 6related to wireless communication, including some or all of the featuresand/or functions related to NOMA communication techniques for a UE. TheUE wireless communication manager 960, or portions of it, may include aprocessor, and/or some or all of the functions of the UE wirelesscommunication manager 960 may be performed by the UE processor 910and/or in connection with the UE processor 910. In some examples, the UEwireless communication manager 960 may be an example of the wirelesscommunication managers 520 described with reference to FIG. 5 or 6.

FIG. 10 shows a block diagram 1000 of a base station 1005 (e.g., a basestation forming part or all of an eNB) for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure. In some examples, the base station 1005 may be an example ofaspects of one or more of the base stations 105, 205, or 305 describedwith reference to FIG. 1A, 1B, 2, 3, or 4A-4C, or aspects of one or moreof the apparatus 705 described with reference to FIG. 7. The basestation 1005 may be configured to implement or facilitate at least someof the base station and/or device features and functions described withreference to FIG. 1A, 1B, 2, 3, 4A-4C, 7, or 8.

The base station 1005 may include a base station processor 1010, a basestation memory 1020, at least one base station transceiver module(represented by base station transceiver(s) 1050), at least one basestation antenna (represented by base station antenna(s) 1055), and abase station NOMA manager 1060. The base station 1005 may also includeone or more of an inter-base station communications manager 1030 and/ora network communications manager 1040. Each of these components may bein communication with each other, directly or indirectly, over one ormore buses 1035.

The base station memory 1020 may include RAM and/or ROM. The basestation memory 1020 may store computer-readable, computer-executablecode 1025 containing instructions that are configured to, when executed,cause the base station processor module 1010 to perform variousfunctions described herein related to wireless communication and/orcommunication using NOMA communication techniques. Alternatively, thecode 1025 may not be directly executable by the base station processor1010 but be configured to cause the base station 1005 (e.g., whencompiled and executed) to perform various of the functions describedherein.

The base station processor 1010 may include an intelligent hardwaredevice, e.g., a CPU, a microcontroller, an ASIC, etc. The base stationprocessor 1010 may process information received through the base stationtransceiver(s) 1050, the inter-base station communications manager 1030,and/or the network communications manager 1040. The base stationprocessor 1010 may also process information to be sent to thetransceiver(s) 1050 for transmission through the antenna(s) 1055, to theinter-base station communications manager 1030, for transmission to oneor more other base stations 1005-a and 1005-b, and/or to the networkcommunications manager 1040 for transmission to a core network 1045,which may be an example of one or more aspects of the core network 130described with reference to FIG. 1A or FIG. 1B. The base stationprocessor 1010 may handle, alone or in connection with the base stationNOMA manager 1060, various aspects of wireless communication for thebase station 1005.

The base station transceiver(s) 1050 may include a modem configured tomodulate packets and provide the modulated packets to the base stationantenna(s) 1055 for transmission, and to demodulate packets receivedfrom the base station antenna(s) 1055. The base station transceiver(s)1050 may, in some examples, be implemented as one or more base stationtransmitters and one or more separate base station receivers. The basestation transceiver(s) 1050 may support communications in the one ormore radio frequency spectrum bands. The base station transceiver(s)1050 may be configured to communicate bi-directionally, via theantenna(s) 1055, with one or more UEs or apparatuses, such as one ormore of the UEs 115, 215, 315, or 915 described with reference to FIG.1A, 1B, 2, 3, 4A-4C or 9, or one or more of the apparatus 515 describedwith reference to FIG. 5. The base station 1005 may, for example,include multiple base station antennas 1055 (e.g., an antenna array).The base station 1005 may communicate with the core network 1045 throughthe network communications manager 1040. The base station 1005 may alsocommunicate with other base stations, such as the base stations 1005-aand 1005-b, using the inter-base station communications manager 1030.

The base station NOMA manager 1060 may be configured to perform and/orcontrol some or all of the features and/or functions described withreference to one or more of FIG. 1A, 1B, 2, 3, 4A-4C, 7, or 8, relatedto wireless communication, including some or all of the features and/orfunctions related to NOMA communication techniques for a base station.The base station NOMA manager 1060, or portions of it, may include aprocessor, and/or some or all of the functions of the base station NOMAmanager 1060 may be performed by the base station processor 1010 and/orin connection with the base station processor 1010.

FIG. 11 is a block diagram of a MIMO communication system 1100 includinga base station 1105 and a UE 1115, in accordance with various aspects ofthe present disclosure. The MIMO communication system 1100 mayillustrate aspects of the wireless communication system 100 describedwith reference to FIG. 1A or FIG. 1B. In some examples, the base station1105 may be an example of aspects of one or more of the base stations105, 205, 305, or 1005 described with reference to FIG. 1A, 1B, 2, 3,4A-4C, or 10, or aspects of one or more of the apparatus 705 describedwith reference to FIG. 7. In some examples, the UE 1115 may be anexample of aspects of one or more of the UEs 115, 215, 315, or 915described with reference to FIG. 1A, 1B, 2, 3, 4A-4C, or 9, or aspectsof one or more of the apparatus 515 described with reference to FIG. 5.The base station 1105 may be equipped with antennas 1134 through 1135,and the UE 1115 may be equipped with antennas 1152 through 1153. In theMIMO communication system 1100, the base station 1105 may be able tosend data over multiple communication links at the same time. Eachcommunication link may be processed according to multiple-antennatechniques including SU-MIMO, MU-MIMO, and/or NOMA. For SU-MIMO, the“rank” of the communication link may indicate the number of spatiallayers used for communication. For example, in a 2×2 MIMO communicationssystem where base station 1105 transmits two spatial layers, the rank ofthe communication link between the base station 1105 and the UE 1115 istwo.

At the base station 1105, a transmit processor 1120 may receive datafrom a data source. The transmit processor 1120 may process the data.The transmit processor 1120 may also generate control symbols and/orreference symbols. A transmit (TX) MIMO processor 1130 may performspatial processing (e.g., precoding) on data symbols, control symbols,and/or reference symbols, if applicable, and may provide output symbolstreams to the transmit modulators 1132 through 1133. Each modulator1132 through 1133 may process a respective output symbol stream (e.g.,for OFDM, etc.) to obtain an output sample stream. Each modulator 1132through 1133 may further process (e.g., convert to analog, amplify,filter, and upconvert) the output sample stream to obtain a DL signal.In one example, DL signals from modulators 1132 through 1133 may betransmitted via the antennas 1134 through 1135, respectively.

At the UE 1115, the UE antennas 1152 through 1153 may receive the DLsignals from the base station 1105 and may provide the received signalsto the demodulators 1154 through 1155, respectively. Each demodulator1154 through 1155 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 1154 through 1155 may further process the input samples(e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 1156may obtain received symbols from all the demodulators 1154 through 1155,perform MIMO detection on the received symbols, if applicable, andprovide detected symbols. A receive processor 1158 may process (e.g.,demodulate, deinterleave, and decode) the detected symbols, providingdecoded data for the UE 1115 to a data output, and provide decodedcontrol information to a processor 1180, or memory 1182.

The processor 1180 may in some cases execute stored instructions toinstantiate a wireless communication manager 1184. The wireless manager1184 may be an example of aspects of the wireless communication manager520, 520-a, or 960 described with reference to FIG. 5, 6, or 9.

On the uplink (UL), at the UE 1115, a transmit processor 1164 mayreceive and process data from a data source. The transmit processor 1164may also generate reference symbols for a reference signal. The symbolsfrom the transmit processor 1164 may be precoded by a transmit MIMOprocessor 1166 if applicable, further processed by the modulators 1154through 1155 (e.g., for SC-FDMA, etc.), and be transmitted to the basestation 1105 in accordance with the transmission parameters receivedfrom the base station 1105. At the base station 1105, the UL signalsfrom the UE 1115 may be received by the antennas 1134 through 1135,processed by the demodulators 1132 through 1133, detected by a MIMOdetector 1136 if applicable, and further processed by a receiveprocessor 1138. The receive processor 1138 may provide decoded data to adata output and to the processor 1140 and/or memory 1142. The processor1140 may in some cases execute stored instructions to instantiate a NOMAmanager 1186. The NOMA manager 1186 may be an example of aspects of theNOMA manger 720, 720-a, or 1060 described with reference to FIG. 7, 8,or 10.

The components of the UE 1115 may, individually or collectively, beimplemented with one or more ASICs adapted to perform some or all of theapplicable functions in hardware. Each of the noted components may be ameans for performing one or more functions related to operation of theMIMO communication system 1100. Similarly, the components of the basestation 1105 may, individually or collectively, be implemented with oneor more ASICs adapted to perform some or all of the applicable functionsin hardware. Each of the noted components may be a means for performingone or more functions related to operation of the MIMO communicationsystem 1100.

FIG. 12 is a flow chart illustrating an example of a method 1200 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1200 is described below withreference to aspects of one or more of the UEs 115, 215, 315, 915, or1115 described with reference to FIG. 1A, 1B, 2, 3, 4A-4C, 9 or 11, oraspects of one or more of the apparatus 515 described with reference toFIG. 5. In some examples, a UE and/or apparatus may execute one or moresets of codes to control the functional elements of the UE and/orapparatus to perform the functions described below. Additionally oralternatively, the UE and/or apparatus may perform one or more of thefunctions described below using special-purpose hardware.

At block 1205, the method 1200 may include receiving TPR signaling. TheTPR signaling may include, for example, one or more values of TPRs for abase modulation layer and an enhancement modulation layer. In someexamples, the TPR signaling may include one or more TPR pairs that eachcontain TPR values for a base modulation layer and an enhancementmodulation layer. The operation(s) at block 1205 may be performed usingthe receiver 510 of FIG. 5, the wireless communication managers 520described with reference to FIG. 5 or 6, the UE antennas 940 and UEtransceiver(s) 930 of FIG. 9, or the UE antennas 1152 through 1153,demodulators 1154 through 1155 and associated receive components of FIG.11.

At block 1210, the method 1200 may include identifying a TS for downlinkcommunications. The identifying a TS may, in some examples, includeidentifying a category of TS for communications. The operation(s) atblock 1210 may be performed using the wireless communication managers520, 960, and/or 1184 described with reference to FIGS. 5, 6, 9, and/or11, or the TS category processor 645 described with reference to FIG. 6.

At block 1215, the method 1200 may include selecting a TPR pairassociated with a TS. The selecting a TPR pair may, in some examples,include selecting a TPR pair based on a category of TS, such as, forexample, selecting a first TPR pair TSs with spatial layer sharing, andselecting a second TPR pair for TSs without spatial layer sharing. Theoperation(s) at block 1215 may be performed using the wirelesscommunication manager 520, 960, and/or 1184 described with reference toFIGS. 5, 6, 9, and/or 11, or the TPR processors 540 described withreference to FIG. 5 or 6.

At block 1220, the method 1200 may include receiving a reference signalfrom base station. The reference signal may include, for example, one ormore of a C-RS, CSI-RS, or DM-RS. The operation(s) at block 1220 may beperformed using the receiver 510 of FIG. 5, the wireless communicationmanager 520 described with reference to FIG. 5 or 6, the UE antennas 964and UE transceiver(s) 930 of FIG. 9, or the UE antennas 1152 through1153, demodulators 1154 through 1155 and associated receive componentsof FIG. 11.

At block 1225, the method 1200 may include estimating channel qualitybased on RS, TPR pair, and base layer and/or enhancement layerreception. The operation(s) at block 1215 may be performed using thewireless communication manager 520, 960, and/or 1184 described withreference to FIGS. 5, 6, 9, and/or 11, or the channel quality estimators550 described with reference to FIG. 5 or 6.

Thus, the method 1200 may provide for wireless communication. It shouldbe noted that the method 1200 is just one implementation and that theoperations of the method 1200 may be rearranged or otherwise modifiedsuch that other implementations are possible.

FIG. 13 is a flow chart illustrating an example of a method 1300 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1300 is described below withreference to aspects of one or more of the base stations 105, 205, 305,1005, or 1105 described with reference to FIG. 1A, 1B, 2, 3, 4A-4C, 10,or 11, or aspects of one or more of the apparatus 705 described withreference to FIG. 7. In some examples, a base station or apparatus mayexecute one or more sets of codes to control the functional elements ofthe base station or apparatus to perform the functions described below.Additionally or alternatively, the base station or apparatus may performone or more of the functions described below using special-purposehardware.

At block 1305, the method 1300 may include determining TPR pairs forbase layer and enhancement layer transmissions. The TPR pairs mayinclude, for example, one or more values of TPRs for a base modulationlayer and an enhancement modulation layer. The operation(s) at block1305 may be performed using the NOMA managers 720, 1060, or 1186 of FIG.7, 8, 10, or 11, or the TPR determination processors 740 of FIG. 7 or 8.

At block 1310, the method 1300 may include transmitting TPR signaling.The TPR signaling may be transmitted using, for example, PDCCH signalingor RRC signaling. The operation(s) at block 1310 may be performed usingthe transmitter 730 described with reference to FIG. 7, the NOMAmanagers 720 described with reference to FIG. 7 or 8, the base stationantennas 1055 and base station transceiver(s) 1050 of FIG. 10, or thebase station antennas 1134 through 1135, modulators 1132 through 1133and associated transmit components of FIG. 11.

At block 1315, the method 1300 may include determining a TS fortransmissions to UE(s). The operation(s) at block 1315 may be performedusing the NOMA manager 720, 720-a, 1060, or 1186 of FIG. 7, 8, 10, or11, the TPR determination processors 740 of FIG. 7 or 8, or the TSdetermination processor 845 of FIG. 8.

At block 1320, the method 1300 may include transmitting DCI indicatingthe TS. The operation(s) at block 1320 may be performed using thetransmitter 730 described with reference to FIG. 7, the NOMA managers720 described with reference to FIG. 7 or 8, the base station antennas1055 and base station transceiver(s) 1050 of FIG. 10, or the basestation antennas 1134 through 1135, modulators 1132 through 1133 andassociated transmit components of FIG. 11.

At block 1325, the method 1300 may include transmitting a referencesignal. The reference signal may include, for example, one or more of aCRS, CSI-RS, or DM-RS. The operation(s) at block 1315 may be performedusing the transmitter 730 described with reference to FIG. 7, the NOMAmanager 720 described with reference to FIG. 7 or 8, the base stationantennas 1055 and base station transceiver(s) 1050 of FIG. 10, or thebase station antennas 1134 through 1135, modulators 1132 through 1133and associated transmit components of FIG. 11.

Thus, the method 1300 may provide for wireless communication. It shouldbe noted that the method 1300 is just one implementation and that theoperations of the method 1300 may be rearranged or otherwise modifiedsuch that other implementations are possible.

In some examples, aspects of one or more of the methods 1200 or 1300described with reference to FIG. 12 or 13 may be combined.

Techniques described herein may be used for various wirelesscommunications systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, andother systems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asCDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and Aare commonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) iscommonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data (HRPD),etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. ATDMA system may implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA system may implement a radiotechnology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA),IEEE 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM™, etc.UTRA and E-UTRA are part of Universal Mobile Telecommunication System(UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are newreleases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, andGSM are described in documents from an organization named “3rdGeneration Partnership Project” (3GPP). CDMA2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). The techniques described herein may be used for thesystems and radio technologies mentioned above as well as other systemsand radio technologies, including cellular (e.g., LTE) communicationsover an unlicensed and/or shared bandwidth. The description above,however, describes an LTE/LTE-A system for purposes of example, and LTEterminology is used in much of the description above, although thetechniques are applicable beyond LTE/LTE-A applications.

The detailed description set forth above in connection with the appendeddrawings describes examples and does not represent all of the examplesthat may be implemented or that are within the scope of the claims. Theterms “example” and “exemplary,” when used in this description, mean“serving as an example, instance, or illustration,” and not “preferred”or “advantageous over other examples.” The detailed description includesspecific details for the purpose of providing an understanding of thedescribed techniques. These techniques, however, may be practicedwithout these specific details. In some instances, well-known structuresand apparatuses are shown in block diagram form in order to avoidobscuring the concepts of the described examples.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connectionwith the disclosure herein may be implemented or performed with ageneral-purpose processor, a digital signal processor (DSP), an ASIC, anFPGA or other programmable logic device, discrete gate or transistorlogic, discrete hardware components, or any combination thereof designedto perform the functions described herein. A general-purpose processormay be a microprocessor, but in the alternative, the processor may beany conventional processor, controller, microcontroller, or statemachine. A processor may also be implemented as a combination ofcomputing devices, e.g., a combination of a DSP and a microprocessor,multiple microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on anon-transitory computer-readable medium. Other examples andimplementations are within the scope and spirit of the disclosure andappended claims. For example, due to the nature of software, functionsdescribed above can be implemented using software executed by aprocessor, hardware, firmware, hardwiring, or combinations of any ofthese. Features implementing functions may also be physically located atvarious positions, including being distributed such that portions offunctions are implemented at different physical locations. As usedherein, including in the claims, the term “and/or,” when used in a listof two or more items, means that any one of the listed items can beemployed by itself, or any combination of two or more of the listeditems can be employed. For example, if a composition is described ascontaining components A, B, and/or C, the composition can contain Aalone; B alone; C alone; A and B in combination; A and C in combination;B and C in combination; or A, B, and C in combination. Also, as usedherein, including in the claims, “or” as used in a list of items (forexample, a list of items prefaced by a phrase such as “at least one of”or “one or more of”) indicates a disjunctive list such that, forexample, a list of “at least one of A, B, or C” means A or B or C or ABor AC or BC or ABC (i.e., A and B and C).

Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable medium that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation,computer-readable media can comprise RAM, ROM, EEPROM, flash memory,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code means in the form of instructions or datastructures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, include compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above are also includedwithin the scope of computer-readable media.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the scope of thedisclosure. Thus, the disclosure is not to be limited to the examplesand designs described herein but is to be accorded the broadest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A method for wireless communication at a userequipment (UE), comprising: determining a first traffic-to-pilot powerratio (TPR) for a base layer for a non-orthogonal channel and a secondTPR for an enhancement layer for the non-orthogonal channel; receivingat least a portion of a reference signal transmitted over thenon-orthogonal channel; and estimating channel quality for the baselayer or the enhancement layer based at least in part on an energy levelof the received reference signal and one or more of the first TPR or thesecond TPR.
 2. The method of claim 1, wherein the determining the firstTPR and the second TPR comprises: determining which of one or moretransmission strategy categories is to be used for downlinktransmissions from a base station to the UE over the non-orthogonalchannel; and selecting the first TPR and the second TPR from one or morepairs of first TPR and second TPR values, each pair associated with oneof the one or more transmission strategy categories.
 3. The method ofclaim 2, further comprising: receiving signaling from the base stationthat provides the one or more pairs of first TPR and second TPR valuesand a transmission strategy category associated with each of the pairsof TPR values.
 4. The method of claim 3, wherein the signaling isreceived via radio resource control (RRC) signaling.
 5. The method ofclaim 2, wherein the determining which of the one or more transmissionstrategy categories is based at least in part on spatial layer sharingof respective transmission strategies, and wherein a first pair of TPRvalues is associated with transmission strategies that use spatial layersharing and a second pair of TPR values is associated with transmissionstrategies that do not use spatial layer sharing.
 6. The method of claim1, wherein the reference signal is one or more of a cell-specificreference signal (CRS) or a channel state information reference signal(CSI-RS).
 7. The method of claim 1, wherein the first TPR and the secondTPR are determined based at least in part on information contained in aphysical downlink control channel (PDCCH), and wherein the informationcontained in the PDCCH comprises one or more of precoding matrixinformation, spatial layer sharing information, TPR information, orinterference cancellation information.
 8. The method of claim 7, whereinthe interference cancellation information comprises an interferencecancellation flag, and wherein a first pair of TPR values are to be usedfor the first TPR and the second TPR when the interference cancellationflag is set, and a second pair of TPR values are to be used for thefirst TPR and the second TPR when the interference cancellation flag iscleared.
 9. The method of claim 7, wherein two or more pairs of TPRvalues are provided to the UE via radio resource control (RRC)signaling, each pair of TPR values including an associated first TPRvalue and second TPR value.
 10. The method of claim 9, wherein the TPRinformation comprises an indication of which of the two or more pairs ofTPR values are to be selected for the first TPR and the second TPR. 11.The method of claim 1, further comprising: receiving a demodulationreference signal (DM-RS) of a data transmission over the non-orthogonalchannel; and demodulating the data transmission based at least in parton a TPR value for the received DM-RS.
 12. The method of claim 11,wherein the TPR value for the received DM-RS is a sum of the first TPRand the second TPR.
 13. The method of claim 11, wherein the TPR valuefor the received DM-RS is independent of one or more of the first TPR orthe second TPR.
 14. The method of claim 11, wherein the DM-RS isassociated with one of a plurality of antenna ports of thenon-orthogonal channel, and wherein the one of the plurality of antennaports is selected for estimating the channel quality based on whetherthe UE is to receive base layer transmissions or enhancement layertransmissions.
 15. The method of claim 14, wherein a transmit power fordata transmissions for the base layer transmissions or the enhancementlayer transmissions corresponds to a DM-RS power of the respective baselayer or enhancement layer.
 16. An apparatus for wireless communicationat a user equipment (UE), comprising: a processor; memory in electroniccommunication with the processor; and instructions stored in the memory,the instructions being executable by the processor to: determine a firsttraffic-to-pilot power ratio (TPR) for a base layer of a non-orthogonalchannel and a second TPR for an enhancement layer for the non-orthogonalchannel; receive at least a portion of a reference signal of thenon-orthogonal channel; and estimate channel quality for the base layeror the enhancement layer based at least in part on an energy level ofthe received reference signal and one or more of the first TPR or thesecond TPR.
 17. The apparatus of claim 16, wherein the instructions arefurther executable by the processor to: determine which of one or moretransmission strategy categories is to be used for downlinktransmissions from a base station to the UE over the non-orthogonalchannel; and select the first TPR and the second TPR from one or morepairs of first TPR and second TPR values, each pair associated with oneof the one or more transmission strategy categories.
 18. The apparatusof claim 17, wherein the instructions are further executable by theprocessor to: receive signaling from the base station that provides theone or more pairs of first TPR and second TPR values and a transmissionstrategy category associated with each of the pairs of TPR values. 19.The apparatus of claim 16, wherein the first TPR and the second TPR aredetermined based at least in part on information contained in a physicaldownlink control channel (PDCCH), and wherein the information containedin the PDCCH comprises one or more of precoding matrix information,spatial layer sharing information, TPR information, or interferencecancellation information.
 20. The apparatus of claim 19, wherein theinterference cancellation information comprises an interferencecancellation flag, and wherein a first pair of TPR values are to be usedfor the first TPR and the second TPR when the interference cancellationflag is set, and a second pair of TPR values are to be used for thefirst TPR and the second TPR when the interference cancellation flag iscleared.
 21. The apparatus of claim 16, wherein the instructions arefurther executable by the processor to: receive a demodulation referencesignal (DM-RS) of a data transmission over the non-orthogonal channel,and demodulate the data transmission based least in part on a TPR valuefor the received DM-RS.
 22. The apparatus of claim 21, wherein the TPRvalue for the received DM-RS is a sum of the first TPR and the secondTPR, or is independent of one or more of the first TPR or the secondTPR.
 23. The apparatus of claim 21, wherein the DM-RS is associated withone of a plurality of antenna ports of the non-orthogonal channel, andwherein the one of the plurality of antenna ports is selected forchannel quality estimation based on whether the UE is to receive baselayer transmissions or enhancement layer transmissions.
 24. A method forwireless communication at a base station, comprising: determining afirst traffic-to-pilot power ratio (TPR) between a base layer datatransmission and a reference signal transmission and a second TPRbetween an enhancement layer data transmission and the reference signaltransmission; and transmitting signaling to one or more user equipments(UEs) indicating the first TPR and second TPR.
 25. The method of claim24, wherein the determining the first TPR and the second TPR comprises:determining one or more transmission strategy categories fortransmissions between the base station and the one or more UEs;determining one or more pairs of TPR values for each transmissionstrategy category, each pair of TPR values comprising an associatedfirst TPR value for base layer data transmissions and an associatedsecond TPR value for enhancement layer data transmissions; andtransmitting one or more reference signals according to the one or morepairs of TPR values.
 26. The method of claim 25, further comprising:transmitting signaling that provides the one or more pairs of TPR valuesand a transmission strategy category associated with each of the one ormore pairs of TPR values.
 27. The method of claim 26, wherein thesignaling is transmitted via radio resource control (RRC) signaling. 28.The method of claim 25, wherein the transmission strategy category isdetermined based on spatial layer sharing of a transmission strategy,and wherein a first pair of TPR values is associated with transmissionstrategies that use spatial layer sharing and a second pair of TPRvalues is associated with transmission strategies that do not usespatial layer sharing.
 29. An apparatus for wireless communication at abase station, comprising: a processor; memory in electroniccommunication with the processor; and instructions stored in the memory,the instructions being executable by the processor to: determine a firsttraffic-to-pilot power ratio (TPR) between a base layer datatransmission and a reference signal transmission and a second TPRbetween an enhancement layer data transmission and the reference signaltransmission; and transmit signaling to one or more user equipments(UEs) indicating the first TPR and second TPR.
 30. The apparatus ofclaim 29, wherein the instructions are further executable by theprocessor to: determine one or more transmission strategy categories fortransmissions between the base station and the one or more UEs;determine one or more pairs of TPR values for each transmission strategycategory, each pair of TPR values comprising an associated first TPRvalue for base layer data transmissions and an associated second TPRvalue for enhancement layer data transmissions; and transmit one or morereference signals according to the one or more pairs of TPR values.